Sorry you are having this problem. Did you also entirely delete the post from the Trash folder as well? It sometimes takes a while for things to be emptied out of the WPcom deleted bin. I’ll tag this for Staff assistance.
Meanwhile, to doublecheck by yourself, try logging out, deleting your browser’s cache and cookies and then logging in again.
Yes, I have done all of that. It has been deleted from trash, and my cookies are clear on the computer I accidentally posted it from. I’ve also had some of my readers contact me about it, so I know it’s not just me.